/// <summary>
/// Removes an item from a context within the overall memory cache of these items. The context must be obtained from the
/// memory cache instance prior to use. This operation is thread safe - all operations are concurrency locked within the
/// confines of the context.
/// </summary>
public void Remove(ITRexSpatialMemoryCacheContext context, ITRexMemoryCacheItem element)
{
lock (_contexts)
{
context.Remove(element);
// Perform some house keeping to keep the cache size in bounds
ItemRemovedFromContext(element.IndicativeSizeInBytes());
}
}
/// <summary>
/// Adds an item into a context within the overall memory cache of these items. The context must be obtained from the
/// memory cache instance prior to use. This operation is thread safe - all operations are concurrency locked within the
/// confines of the context.
/// </summary>
public CacheContextAdditionResult Add(ITRexSpatialMemoryCacheContext context, ITRexMemoryCacheItem element, long invalidationVersion)
{
lock (_contexts)
{
// If the invalidation version of a sub grid derivative being added to the cache does not match the current invalidation version
// then prevent it being added to the cache, and return a negative result to indicate the refusal
if (invalidationVersion != context.InvalidationVersion)
{
_log.LogInformation($"Sub grid derivative at {element.CacheOriginX}:{element.CacheOriginY} not added to cache context due to invalidation version mismatch ({invalidationVersion} vs {context.InvalidationVersion})");
return(CacheContextAdditionResult.RejectedDueToInvlidationVersionMismatch);
}
if (context.MarkedForRemoval)
{
context.Reanimate();
}
var result = context.Add(element);
if (result == CacheContextAdditionResult.Added)
{
// Perform some house keeping to keep the cache size in bounds
ItemAddedToContext(element.IndicativeSizeInBytes());
while (_currentSizeInBytes > MaxSizeInBytes && !MRUList.IsEmpty())
{
MRUList.EvictOneLRUItem();
}
}
return(result);
}
}
